As disclosed, e.g., in U.S. Pat. Nos. 3,244,758 (Eberhardt) and 4,179,580 (Cobb) and in European Patent No. 128001 (Kudoh et al.), it is known that supported alkali metals, including potassium and sodium-potassium alloys, are useful as catalysts in the coupling of ethylenically-unsaturated hydrocarbons with aromatic hydrocarbons having an active hydrogen on a saturated alpha-carbon. The supported alkali metals are more effective than the corresponding unsupported alkali metals in such reactions but are still not as effective as might be desired.
Claff et al., Journal of Organic Chemistry. Vol. 20, pp. 440-442 and 981-986 (1955) disclose the use of sodium oxide in the metalation of toluene by potassium.
British Patent No. 902,043 (Esso) teaches that a calcined mixture of a Group IA metal and a Group II metal oxide can be used to catalyze the alkylation of an aromatic hydrocarbon with an alkene.
Copending applications Ser. No. 356,186 (Smith), filed May 24, 1989, and Ser. No. 372,261 (Smith), filed June 27, 1989, disclose the use of alkali metal oxides as co-catalysts for the coupling of ethene and/or propene with aromatic hydrocarbons having an active hydrogen on a saturated .alpha.-carbon in the presence of a supported alkali metal as a catalyst.